It looks at Leonardo from the view-point of his ne'er-do-well apprentice and servant Giacomo, known forever to history as Salai, whom Leonardo describes as "lying, thieving, gluttonous", but who none the less spends most of his life in a complex relationship with the Maestro. Along the way we encounter Machievelli, Cesare Borgia, Michelangelo, Katerina (a dwarf with a unique talent!) and the model for the painting Mona Lisa.